This disclosure relates to a package for two or more material components or substances intended to be mixed together immediately prior to use. It is particularly adapted to the packaging of chemically reactive substances, such as thermosetting adhesives, filler compositions and other resin formulations.
Such thermosetting materials typically comprise a base composition to which is added a curing agent or catalyst which hardens the mixture of the two. Because the curing time is relatively short, these material components can't be premixed and must be delivered to the ultimate user in separate containers or compartments.
The package can also be used for storing and mixing of other products including two or more material components, such as base mixtures and coloring components, extenders, texturing components or other materials required to selectively desirable in the final mixture. As an example, the package might contain a coating composition with one or more separate coloring agents which can be selectively chosen by the ultimate user for final mixing in the present package before application of the coating material.
Storage of chemically reactive substances such as thermosetting resin components has posed many difficulties in package design because of the inherent nature of the substances. They must be completely isolated from one another, since even small amounts of the curing composition will effect a reaction and ultimately harden the base composition. The general practice is to store and deliver individual components or thermosetting compositions in separate containers such as cans or tubes.
In the case of thermosetting, resin fillers, the base composition or putty and the curing agent are supplied in two separate containers. The user removes a selected amount of each material and mixes them in a third container as required for application. This necessitates the use of separate mixing containers and risks inaccurate measurement of the required amounts of both material compositions. In many instances the relative amount of material are critical to the proper functioning of the mixture and inaccurate mixing can lead to failure in the thermosetting system.
Prior patents do show packages for holding two reactive ingredients in a tray structure having an outer removable cover. U.S. Pat. No. 4,008,803 to Smith shows two separate compartments for holding a resin and hardener, together with a separate mixing compartment and a tool for cutting the covering sacs and handling of the chemicals. The tool itself is not shaped to specifically complement the shapes of the package compartments.
Prior U.S. Patent to Marckardt, U.S. Pat. No. 3,756,386 shows a multichamber container with a single recess in the body of the container and a small recess formed in its cover for holding two components. To use this package, the wall separating these recesses is broken and material is squeezed from the smaller recess into the main compartment for mixing.
The U.S. Pat. No. to Franck, 4,081,077 discloses a compartmented package where a mixing tool separates recesses into compartments. The mixing tool serves as a divider to isolate the compartments. Its outer configuration does not otherwise complement the shape of the recesses.
A final patent showing prior use of compartmentalized tray packages in U.S. Pat. No. 3,618,751. It relates to crushing and administering of pills in powder form.
The package illustrated and described herein presents two or more separate compartments arranged about an open tray in close proximity to one another. Each compartment is formed as a depression in the tray, and is adapted to hold a predetermined quantity of material within it. One of the compartments serves a second purpose as a mixing receptacle into which material from the other compartment or compartments can be transferred and mixed with its contents prior to use. The package also comprises a complementary paddle or mixing tool. The upwardly facing ramps presented by the compartments or depressions within the tray are complementary to the edge configurations of the mixing tool to facilitate both removal and mixing of the material components.
More specifically, the present disclosure relates to a package in the form of a rigid tray preferably formed or molded from synthetic resin material. The tray has two or more depressions formed therein for containing two or more separate material components. It also has a planar upper surface defining the upper extremities of the depressions. A cover sheet is secured about the periphery of each depression to enclose the package and physically isolate the material components from one another for storage and shipping purposes. The tray includes an integral mixing tool or paddle. It is joined to it along a line of weakness which permits the tool to be manually separated from the tray prior to its use.